mbedtls/tests/suites/test_suite_ctr_drbg.function
Gilles Peskine ef0624f791 ctr_drbg tests: make input sizes flexible
The ctr_drbg_validate_xxx test functions had hard-coded sizes for the
entropy and the output size. Generalize the sizes.

Keep track of the current entropy size.

Unhexify the expected output and compare with the actual output,
rather than hexifying the actual output and comparing the hex.
2018-08-21 18:02:03 +03:00

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8.3 KiB
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/* BEGIN_HEADER */
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "string.h"
static size_t test_offset_idx;
static size_t test_max_idx;
static int mbedtls_test_entropy_func( void *data, unsigned char *buf, size_t len )
{
const unsigned char *p = (unsigned char *) data;
if( test_offset_idx + len > test_max_idx )
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
memcpy( buf, p + test_offset_idx, len );
test_offset_idx += len;
return( 0 );
}
/* END_HEADER */
/* BEGIN_DEPENDENCIES
* depends_on:MBEDTLS_CTR_DRBG_C
* END_DEPENDENCIES
*/
/* BEGIN_CASE */
void ctr_drbg_special_behaviours( )
{
mbedtls_ctr_drbg_context ctx;
unsigned char output[512];
unsigned char additional[512];
mbedtls_ctr_drbg_init( &ctx );
memset( output, 0, sizeof( output ) );
memset( additional, 0, sizeof( additional ) );
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx,
output, MBEDTLS_CTR_DRBG_MAX_REQUEST + 1,
additional, 16 ) ==
MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG );
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx,
output, 16,
additional, MBEDTLS_CTR_DRBG_MAX_INPUT + 1 ) ==
MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
TEST_ASSERT( mbedtls_ctr_drbg_reseed( &ctx, additional,
MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + 1 ) ==
MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
mbedtls_ctr_drbg_set_entropy_len( &ctx, ~0 );
TEST_ASSERT( mbedtls_ctr_drbg_reseed( &ctx, additional,
MBEDTLS_CTR_DRBG_MAX_SEED_INPUT ) ==
MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
exit:
mbedtls_ctr_drbg_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void ctr_drbg_validate_pr( data_t * add_init, data_t * entropy,
data_t * add1, data_t * add2,
char *result_string )
{
mbedtls_ctr_drbg_context ctx;
unsigned char buf[512];
unsigned char result[512];
size_t entropy_len, add_init_len, add1_len, add2_len, result_len;
mbedtls_ctr_drbg_init( &ctx );
entropy_len = unhexify( entropy, entropy_string );
result_len = unhexify( result, result_string );
test_offset_idx = 0;
test_max_idx = entropy_len;
/* CTR_DRBG_Instantiate(entropy[:entropy_len/3], nonce, perso, <ignored>)
* where nonce||perso = add_init[add_init_len] */
TEST_ASSERT( mbedtls_ctr_drbg_seed_entropy_len( &ctx, mbedtls_test_entropy_func, entropy, add_init, add_init_len, entropy_len / 3 ) == 0 );
mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
/* CTR_DRBG_Generate(result_len * 8 bits, add1[:add1_len]) -> buf */
/* Then reseed because of prediction resistance. */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add1, add1_len ) == 0 );
/* CTR_DRBG_Generate(result_len * 8 bits, add2[:add2_len]) -> buf */
/* Then reseed because of prediction resistance. */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add2, add2_len ) == 0 );
TEST_ASSERT( memcmp( buf, result, result_len ) == 0 );
exit:
mbedtls_ctr_drbg_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void ctr_drbg_validate_nopr( data_t * add_init, data_t * entropy,
data_t * add1, data_t * add_reseed,
char *add2_string, char *result_string )
{
mbedtls_ctr_drbg_context ctx;
unsigned char buf[512];
unsigned char result[512];
size_t entropy_len, add_init_len, add1_len, add_reseed_len, add2_len, result_len;
mbedtls_ctr_drbg_init( &ctx );
entropy_len = unhexify( entropy, entropy_string );
result_len = unhexify( result, result_string );
test_offset_idx = 0;
test_max_idx = entropy_len;
/* CTR_DRBG_Instantiate(entropy[:entropy_len/2], nonce, perso, <ignored>)
* where nonce||perso = add_init[add_init_len] */
TEST_ASSERT( mbedtls_ctr_drbg_seed_entropy_len( &ctx, mbedtls_test_entropy_func, entropy, add_init, add_init_len, entropy_len / 2 ) == 0 );
/* CTR_DRBG_Generate(16 * 8 bits, add1[:add1_len]) -> buf */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add1, add1_len ) == 0 );
/* CTR_DRBG_Reseed(entropy[entropy_len/2:entropy_len], add_reseed[:add_reseed_len]) */
TEST_ASSERT( hexcmp( buf, result_str->x, 16, result_str->len ) == 0 );
/* CTR_DRBG_Generate(16 * 8 bits, add2[:add2_len]) -> buf */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add2, add2_len ) == 0 );
TEST_ASSERT( memcmp( buf, result, result_len ) == 0 );
exit:
mbedtls_ctr_drbg_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void ctr_drbg_entropy_usage( )
{
unsigned char out[16];
unsigned char add[16];
unsigned char entropy[1024];
mbedtls_ctr_drbg_context ctx;
size_t i, reps = 10;
size_t last_idx;
mbedtls_ctr_drbg_init( &ctx );
test_offset_idx = 0;
test_max_idx = sizeof( entropy );
memset( entropy, 0, sizeof( entropy ) );
memset( out, 0, sizeof( out ) );
memset( add, 0, sizeof( add ) );
/* Init must use entropy */
last_idx = test_offset_idx;
TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, mbedtls_test_entropy_func, entropy, NULL, 0 ) == 0 );
TEST_ASSERT( last_idx < test_offset_idx );
/* By default, PR is off and reseed_interval is large,
* so the next few calls should not use entropy */
last_idx = test_offset_idx;
for( i = 0; i < reps; i++ )
{
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) - 4 ) == 0 );
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, out, sizeof( out ) - 4,
add, sizeof( add ) ) == 0 );
}
TEST_ASSERT( last_idx == test_offset_idx );
/* While at it, make sure we didn't write past the requested length */
TEST_ASSERT( out[sizeof( out ) - 4] == 0 );
TEST_ASSERT( out[sizeof( out ) - 3] == 0 );
TEST_ASSERT( out[sizeof( out ) - 2] == 0 );
TEST_ASSERT( out[sizeof( out ) - 1] == 0 );
/* Set reseed_interval to the number of calls done,
* so the next call should reseed */
mbedtls_ctr_drbg_set_reseed_interval( &ctx, 2 * reps );
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( last_idx < test_offset_idx );
/* The new few calls should not reseed */
last_idx = test_offset_idx;
for( i = 0; i < reps / 2; i++ )
{
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, out, sizeof( out ) ,
add, sizeof( add ) ) == 0 );
}
TEST_ASSERT( last_idx == test_offset_idx );
/* Call update with too much data (sizeof entropy > MAX(_SEED)_INPUT)
* (just make sure it doesn't cause memory corruption) */
mbedtls_ctr_drbg_update( &ctx, entropy, sizeof( entropy ) );
/* Now enable PR, so the next few calls should all reseed */
mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( last_idx < test_offset_idx );
/* Finally, check setting entropy_len */
mbedtls_ctr_drbg_set_entropy_len( &ctx, 42 );
last_idx = test_offset_idx;
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( test_offset_idx - last_idx == 42 );
mbedtls_ctr_drbg_set_entropy_len( &ctx, 13 );
last_idx = test_offset_idx;
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( test_offset_idx - last_idx == 13 );
exit:
mbedtls_ctr_drbg_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_FS_IO */
void ctr_drbg_seed_file( char * path, int ret )
{
mbedtls_ctr_drbg_context ctx;
mbedtls_ctr_drbg_init( &ctx );
TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, rnd_std_rand, NULL, NULL, 0 ) == 0 );
TEST_ASSERT( mbedtls_ctr_drbg_write_seed_file( &ctx, path ) == ret );
TEST_ASSERT( mbedtls_ctr_drbg_update_seed_file( &ctx, path ) == ret );
exit:
mbedtls_ctr_drbg_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
void ctr_drbg_selftest( )
{
TEST_ASSERT( mbedtls_ctr_drbg_self_test( 1 ) == 0 );
}
/* END_CASE */